Collimator lenses that are formed in glass or plastics are well known. FIG. 1 illustrates a first prior art collimator lens 10. The first prior art collimator lens 10 includes a hyperboloid surface 12 and a plane surface 14. A light source 16, such as a laser, generates a light beam 18 that generally diverges with a beam angle or width. After passing through the prior art lens 10, the light beams 20 are generally parallel. It is noted that the hyperboloid surface 12 performs the collimating function.
FIG. 2 illustrates a second prior art collimator lens 30. The second prior art collimator lens 30 includes a plane surface 32 and a convex surface 34. A light source 36, such as a laser, generates a light beam 38 that generally diverges with a first beam angle. After passing through the prior art lens 30, the light beams 32 are generally parallel. It is noted that the convex surface 34 performs the collimating function.
Unfortunately, these two prior art approaches suffer from several drawbacks or disadvantages. First, in compact space-limited applications, such as an optical mouse product, the prior art collimators consume too much space along the axis from the light source to the surface from which the light beam reflects. Second, there are systems and applications where a titled beam is required. However, the tilting of the laser imposes severe tolerance conditions that are difficult and costly to achieve in manufacturing.
Based on the foregoing, there remains a need for an optic element that overcomes the disadvantages set forth previously.